The present invention relates to mechanisms for performing a process for a removable medium. Particularly, the present invention relates to mechanisms for performing a process for a removable medium in a drive for driving the removable medium.
In a drive using a removable medium such as a tape medium, when an error of writing of data on a medium or reading out of data from a medium occurs, it is not easy to judge whether the error occurs due to the drive or the medium. A conceivable reason thereof is that the occurrence tendency of errors varies depending on combinations of a drive and a medium. Further, even with a combination of the same drive and medium, the occurrence tendency of errors may vary depending on a type of an executed operation or an environment of the drive at the time of execution.
In view of this, in order to check over the occurrence tendency of errors, some type of tape drive stores information of error histories of each cartridge which the drive has used recently in a nonvolatile memory in the drive, which error histories are at the time of the use when the drive used each cartridge. In the present specification, the information of error histories related to this drive is referred to as “drive error information”. Further, in a cartridge of the tape drive, information of error histories at the time of use of the cartridge is recorded and stored in a tape medium in the cartridge for each drive that has used the cartridge recently. In the present specification, information of error histories related to this cartridge is referred to as “cartridge error information.” When a cartridge is loaded in a drive, cartridge error information is read out from a tape medium in the cartridge into a random access memory (RAM) in the drive so as to be referred to or updated by firmware of the drive. Then, when the cartridge is unloaded from the drive, the cartridge error information is written back into the tape medium in the cartridge from the RAM in the drive.
For example, in a case where an error occurs when a cartridge Ca is used in a drive Da, the drive Da can know an error rate at the time of use of the cartridge Ca from its drive error information. As a result, if a mean value of error rates about the cartridge Ca is higher than mean values of error rates about all cartridges, it can be judged that a combination of the drive Da with the cartridge Ca is bad.
However, it is difficult to judge by merely drive error information of the drive Da whether errors have occurred because of poor quality of the drive, error have occurred because of poor quality of the cartridge, or errors have accidentally occurred at that time because of another factor.
Here, if pieces of drive error information of other drives Db and Dc and pieces of cartridge error information of others cartridge Cb and Cc can be obtained, the number of parameters of data to be used for judgment will increase. As a result, it is possible to judge more accurately which is more likely to have poor quality, the drive or the cartridge.
Conventionally, in order to generally judge an error factor based on pieces of error information held by a plurality of drives or a plurality of media, special software prepared outside those drives or a structure for collecting pieces of error information of a library using those drives are used.
Further, as well as the judgment of the error factor, in a case where judgment on errors such as judgment on an area on a medium where errors are easy to occur, a recovery method at the time when an error occurs, and the like is performed based on pieces of error information held by a plurality of drives or a plurality of media, special software provided outside the drives or a structure for collecting pieces of error information of a library have been used.
Note that it has been known that a library collects information from each drive, as a technique disclosed patent application publications (for example, see Patent Documents 1 and 2).
In the technique of Patent Document 1, a library includes MIN which is connected to CAS and DEE of an import/export apparatus, DM of a recording/playback apparatus, and ADR, AMC, and CSV of a control apparatus so as to collect trace information of each MPU provided in each of them and to store the trace information in a trace information storage apparatus.
In the technique of Patent Document 2, a memory-information reading processing section of a magnetic tape library apparatus reads information related to reading of data or writing of data which the magnetic tape drive apparatus has performed on a magnetic tape cartridge, from a memory of the magnetic tape cartridge which includes an electromagnetic tape, and a maintenance/replacement judging section performs judgment on maintenance or replacement of the magnetic tape drive apparatus based on the information thus read.
[Patent Document 1]
Japanese Unexamined Patent Publication No. 11-224450
[Patent Document 2]
Japanese Unexamined Patent Publication No. 2006-164445